Thursday, July 12, 2018

Our friends at Control Instruments Corporation have put together an excellent Table of Gases web page that includes chemical formula, chemical properties, and what type of detection detection technology (Catalytic, Flame Temperature Analyzer, Flame Ionization Detector, British Thermal Unit) is applicable. We find is a handy reference when researching properties of gases.

Control Instrument Corporation manufacturers gas detection instruments for safety and environmental protection. Control Instruments products are installed and used under the most demanding conditions, from oil pipelines in the Arctic to drilling wells in the desert.

Tuesday, May 17, 2016

A large manufacturer of adhesives needed to reduce energy costs in their plant. A large part of their energy cost was literally going out the window in the ventilation system and associated fuel costs. The heated air they produced for ventilation was expensive, yet is was necessary in order to comply with the NFPA's (National Fire Protection Association) standard of 25% LFL (lower explosive limit) on solvent vapor concentrations.

The 25% LFL applies to areas using just ventilation, but increases to 50% LFL if a continuous flammability analyzer is installed. If the manufacturer installed vapor analyzers, they could reduce the amount of energy on ventilation and fuel.

To meet the objective of lowering energy costs, the company installed PrevEx Flammability Analyzers, manufactured by Control Instrument Corporation, on each adhesive dryer. The PrevEx is a flammability analyzer for lower flammable limit monitoring (LFL/LEL) designed to provide fast response time (less than 1 second), capable of quickly changing gas concentrations, and with failsafe performance.

PrevEx flammability analyzers use a heated flame cell and an integrated controller that continuously measures total flammable vapor concentrations from 0 to 100% of the Lower Flammable Limit (LFL) range. To avoid condensation during sampling, the entire analyzer pneumatic assembly is heated.

A PrevEx analyzer was fitted on each printing press dryer to detect the possibility of solvent vapor accumulation. The PrevEx analyzers were chosen because of their "Universal Calibration" feature which prevents downtime due to re-calibration requirements.

By installing the flammability analyzers, the manufacturer was able to decrease ventilation and the associated energy costs while still staying in compliance with the NFPA code.

To understand more about flammability analyzers, look over the product document below:

The customer is global supplier of vibration damping and sealing products for the automotive, consumer electronic and industrial markets that sells elastomer-coated metals, gaskets, brake shims and automotive and brake noise insulators. They also manufacture a variety of sealing materials, such as deck plates, oil filter adaptors, water outlets, pumps, relief valves, and rear cam and surge tank covers.

In their process solvents are applied to a web material. The web material contains PTFE and/ or rubber based adhesives and at times silicone. The main solvent component used is MEK which is not a high flash point solvent. Flammability analyzers were being used to monitor the flammability levels of the varying solvent levels in the zone’s atmosphere.

The flammability analyzers were mounted fairly far from the oven because of operating temperatures, and subsequently had long sampling lines. The last three zones were very challenging due to the distance and the use PTFE, silicones and other resins. Because the lines were so long, they were clogging from VOCs and vaporized web material and required the line to be shut down and cleaned. The downtime meant loss of production and loss of profits. The customer tried adding end-of-line filters on all sample tubing, which helped, but didn't solve the problem.

To solve the problem, the customer upgraded to a new flammability analyzer (a CIC model SNR674) rated for operating temperatures high enough (392 F) to keep all the elements in a vapor state and designed for use in a dirty environment. Theses new flammability analyzers are mounted directly on the oven wall eliminating the long sample lines. By keeping the sample lines as short as possible they were able to minimize the VOC condensation and eliminate the clogging.